Coloration of materials



aflinity for the cellulose Patented Sept. 9, 1941 v 2,255,130 COLORATION or MATERIALS George W. Seymour and George C. Ward, Cumberland, Md., assignors to Celanese Corporation of America,

a corporation of Delaware No Drawing. Application September 21,1939,

Serial No. 295,910

9 Claims.

This invention relates to improvements in the coloration or dyeing of materials such as films, fibers, yarns, fabrics or filaments made of or containing cellulose acetate or other organic derivatives of cellulose whereby fast colorations or dyeings are obtained.

An object of this invention is the dyeing of organic derivative of cellulose textile materials to obtain fast colorations. Another object ofthis invention is the'coloration of organic derivative of cellulose textile materials by means of dyestufis diazotized and coupled on the fiber to obtain fast colorations of proper shade. A further object of this invention is the conversion of dark blue, dark green and dark purple dyeings on organic derivative of cellulose materials by means of dyestufis which normally have little derivative into dyeings which are very fast. 'Other objects and advantages of the invention will appear from the following detailed description and appended claims.

In the coloration of textile materials it is of course highly desirable that colorations produced should be fast to light, perspiration, acid, sea water and washing. A rather wide range of dyestuffs suitable for dyeing organic derivatives of cellulose commercially satisfactory in fast shades have been developed, but the colorations obtained in certain blue, green and purple shades left considerable to be desired in their fastness properties. It is of course obvious that these shades are very valuable and that a satisfactory method of obtaining these colors in fast shades on organic derivative of cellulose materials is of great commercial importance.

The developed shades of the naphthol colors with certain bases are well known and heretofor have been used entirely on cotton fabrics.

When attempts were made to adapt these particular colors for use on cellulose acetate materials for dark blues, greens and purples it was found that they could not be so used since the proper shade of the finished dyestufi was not obtained. Moreover, the colorations obtained were not fast to light.

We have now found that dark blue, green and purple colorations on organic derivative of cellulose materials of a very high degree of fastness may be obtained by treating such materials with certain bases useful on cotton, diazotizing and coupling the diazotized base on the fiber with a Naphthal AS (arylides of 2:3 hydroxynaphthoicacid) type of developer and then subjecting the colored cellulose derivative material to a further action such as steaming under suitable condi- 55 tions. The first portion of the process results in a false shade which does not match the color obtained on cotton with this dyestuiT. This false shade can be converted or rearranged to the proper or true shade by the final or subsequent According to the present invention a cellulose acetate or other cellulose derivative material which has been colored with an unstable developed shade of the Naphthol AS class is subjected to a reduction treatment and steaming in order to develop the proper. shade of good fastness properties. This treatment apparently converts or rearranges the intermediate, unstable coupling of the false shade into a stable coupling resulting in the proper shade. One manner of effecting this rearrangement or conversion of the color to the true shade of good fastness comprises padding the dyed fabric with a printing paste containing an acid reducing medium in a suitable gum and then, without any pre-drying, subjecting the padded fabric to moist steam in an ager. The fabric is then washed and finished in the usual manner.

The textile material to be treated may be in the form of fabric containing yarns of organic derivatives of cellulose such as organic esters of cellulose and cellulose ethers but it may also be in the form of yarns or filaments. Examples of organic esters of cellulose are cellulose acetate, cellulose formate, cellulose propionate, cellulose butyrate or mixed esters such as cellulose acetate propionate and cellulose acetate butyrate.

The process is also applicable to partially sapon ified cellulose esters. Examples of cellulose ethers are methyl cellulose, ethyl cellulose and benzyl cellulose. The textile material treated may be made entirely of the cellulose derivative or it may be a mixed material containing'for example, cotton, natural silk, regenerated cellulose or wool in addition to the cellulose derivative. By proper selection of dyestuffs various novel effects can be obtained with such mixed material.

As pointed out above, the present invention is predicated upon the discovery that the blue,

green and purple dyeings obtained on cellulose acetate materials by means of certain diazotlzable bases suitable for coloring cotton diazotized and coupled on the fabric with Naphthol AS developers are not true or proper shades as observed on cotton and the further discovery that these colorations can be converted or rearranged to the proper or true shade by a comparatively simple and economical treatment. This treatment comprises broadly the padding of the fabric as it comes from the developing bath with a printing paste containing a reducing agent and then steaming the fabric with moist steam for a comparatively short period. The fabric is then washed and finished as normally. This invention is of especial value in obtaining fast green, blue and purple shades with dyestuffs which had heretofore been considered inapplicable to cellulose acetate.

The present process is applicable to colorations on cellulose acetate obtained with Fast Blue BB Base (4 benzoylamino 2:5 diethoxy-aniline), Fast Blue RR Base (4-benzoylamino-2z5-dimethoxy-aniline), Fast Corinth LB Base (2- chlor-4-benzoylamino-S-methoxy-aniline), Fast Violet B Base (6-benzoylamino-4-methoxy-3- aminotoluene), Variamine Blue B (4-amino-4'- methoxy-diphenylamine) and Fast Garnet GBC Base (amino-azotoluene), especially when cou' pled with Naphthol AS (anilide of 2:3-hydroxynaphthoic acid) or Naphthol AS/D (o-toluidide of 2:3-hydroxynaphthoic acid). Other developers of the Naphthol AS type can be used such as Naphthol AS/OL (o-aniside of 2 El-hydroxynaphthoic acid) or Naphthol AS/GR (o-toluidide of 2-hydroxyanthracene-3 carboxylic acid) but the best results are obtained using the above combinations.

Some of the combinations and shade changes 4% zine sulphoxylate formaldehyde, 4% citric acid, 10% gum tragacanth and 82% water and,

then steamed at 100 C. with moist steam for 6 to 10 minutes. The true shade, bright blue, is obtained at the end of this period and the fabric is then washed and finished as normally.

Example II A cellulose acetate fabric was treated as in Example I but using Naphthol AS/D as the developer. The developed shade was deep reddish blue and the final shade was deep blue.

Example III Example IV A cellulose acetate fabric was treated as in Example I using Fast Garnet GBC Base as the diazotizable base and Naphthol AS as the developer. The developed shade was red and the final shade was dull reddish brown.

While zinc sulphoxylate formaldehyde was found to be the most suitable reducing agent, other reducing agents such as sodium sulphoxylate formaldehyde, oxalic acid and the like may also be used.

When other reducing agents are utilized care must be taken not to employ a reducing agent whose action is too vigorous. The reduction is most satisfactorily and completely carried out by moist steaming at 100 C.

Theforegoing detailed description is given merely by way of illustration and many variations may be made therein without departing which occur are as follows: from the spirit of our invention.

Shade Base Developer Out of developer After reduction 1 Fast Blue BB Base Naphthol AS Deep purple Bright blue.

2 0 Naphthol AS/D. Deep reddish blue... Deep blue.

3 Naphthol AS/O Deep purple Reddish blue.

4 Fa t Blue RR Base Naphthol AS. Beddish violet Do.

5 do Naphthol AS/D... do Deep blue 6 ..do Naphthol AS/GR Yellow-brown. Pale green.

7 Fast Corinth LB Base Naphthol Reddish violet.

8 .do Naphthol ASID D0.

9 Fast Garnet GBC Base. Naphthol AS. Dull reddish brown. 10 .-do Naphthol AS/D Do. 11 Fast Violet B Base Naphthol ASID Reddish violet. l2 Variamine Blue B Naphthol AS Light blue.

In order to further illustrate our invention, but without being limited thereto, the followin examples are given:

Example I A cellulose acetate fabric is introduced in a bath containing 2% Fast Blue BB Base, 6% Turkey red oil and /2;% of soda ash. The fabric is kept in the bath for two hours at 85 C., after which it is rinsed well. The fabric is then diazotized in 3 to 5 grams per liter of hydrochloric acid and 3 grams per liter of sodium nitrite for hour at 10-18" C. After rinsing once in cold water it is developed with 4% Naphthol AS, 8%

Turkey red oil and suflicient caustic soda to give the bath a pH of 7.5 to 8.5, the fabric .being entered at- C. and maintained at this temperature for one hour. The color on the fabric is now a deep purple. The fabric is then padded on a regular printing machine or a regular padding machine with a pad roll of paste containing jecting the material to reduction and steaming,

said reduction being insufficiently vigorous to effect discharge of the dye.

2. Process for dyeing cellulose acetate textilematerials, which comprises treating the cellulose acetate material with a suitable diazotizable base, diazotizing, coupling the same on the fiber with an o-hydroxy carboxylic arylamide which couples in ortho-position to the hydroxy group, and subjecting the material to reduction and moist steaming, said reduction being insufliciently vigorous to effect discharge of the dye.

3. Process for dyeing cellulose acetate textile materials, which comprises treating the cellulose acetate material with a suitable diazotizable base, diazotizing, coupling the same on the fiber with an arylamide of 2:3 hydroxynaphthoic acid, and subjecting the material to reduction and moist steaming, said reduction being insufiicient- 1y vigorous to effect discharge of the dye.

4. Process for dyeing cellulose acetate textile materials, which comprises treating the cellulose acetate material with a suitable diazotizable base, diazotizing, coupling the same on the fiber with an arylamide of 2:3 hydroxynaphthoic acid, treating the material with a composition containing acid and a reducing agent, and then treating the material with moist steam, said reducing treatment being insufficiently vigorous to effect discharge of the dye.

5. Process for dyeing cellulose acetate textile materials, which comprises treating the cellulose acetate material with a suitable diazotizable base, diazotizing, coupling the same on the fiber with an arylamide of 2 :3 hydroxynaphthoic acid, padding the material with a composition containing zinc sulphoxylate formaldehyde, and then treating the material, without predrying with moist steam, the strength of the composition containing zinc sulphoxylate formaldehyde being insuficient to efiect discharge of the dye.

6. Process for dyeing cellulose acetate textile materials, which comprises treating the cellulose acetate material with a suitable diazotizable base, diazotizing, coupling the same on the'fiber with an arylamide of 2:3 hydroxynaphthoic acid, padding the material with a composition prepared by incorporating acid with zinc sulphoxylate formaldehyde, water and a thickener, and then treating the material, without predrying, with moist steam, the strength of the composition containing zinc sulphoxylate formaldehyde being insuflicient to effect discharge of the dye.

7. Process for dyeing cellulose acetate textile materials, which comprises treating the cellulose acetate material with a 4-benzoylamino-aniline, diazotizing, coupling the same on the fiber with an anilide of 2:3 hydroxynaphthoic acid, padding the material with a composition containing zinc sulphoxylate formaldehyde, and then treating the material, without predrying with moist steam, the strength of the composition containing zinc sulphoxylate formaldehyde being insuflicient to effect discharge of the dye.

8. Process for dyeing cellulose acetate textile materials, which comprises treating the cellulose acetate material with an aminoazobenzene, diazotizing, coupling the same on the fiber with an anilide of 2:3 hydroxynaphthoic acid, padding the material with a composition containing zinc sulphoxylate formaldehyde, and then treating the material, without predrying, with moist steam, the strength of the composition containing zinc sulphoxylate formaldehyde being insuflicient to efiect discharge of the dye.

9. Process for dyeing cellulose acetate textile materials, which comprises treating the cellulose acetate material with an aminodiphenylamine, diazotizing, coupling the same on the fiber with an anilide of 2:3 hydroxynaphthoic-acid, padding the material with a composition containing zinc sulphoxylate formaldehyde, and then treating the material, without predrying, with moist steam, the strength of the composition containing zinc sulphoxylate formaldehyde being insuflicient to effect discharge of the dye.

GEORGE W. SEYMOUR. GEORGE C. WARD. 

